Zygosaccharomyces Rouxii

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Hana Sychrová - One of the best experts on this subject based on the ideXlab platform.

  • a set of plasmids carrying antibiotic resistance markers and cre recombinase for genetic engineering of nonconventional yeast Zygosaccharomyces Rouxii
    Yeast, 2019
    Co-Authors: Melissa Bizzarri, Hana Sychrová, Stefano Cassanelli, Michala Duskova, Lisa Solieri
    Abstract:

    The so-called nonconventional yeasts are becoming increasingly attractive in food and industrial biotechnology. Among them, Zygosaccharomyces Rouxii is known to be halotolerant, osmotolerant, petite negative, and poorly Crabtree positive. These traits and the high fermentative vigour make this species very appealing for industrial and food applications. Nevertheless, the biotechnological exploitation of Z. Rouxii has been biased by the low availability of genetic engineering tools and the recalcitrance of this yeast towards the most conventional transformation procedures. Centromeric and episomal Z. Rouxii plasmids have been successfully constructed with prototrophic markers, which limited their usage to auxotrophic strains, mainly derived from the Z. Rouxii haploid type strain Centraalbureau voor Schimmelcultures (CBS) 732T . By contrast, the majority of industrially promising Z. Rouxii yeasts are prototrophic and allodiploid/aneuploid strains. In order to expand the genetic tools for manipulating these strains, we developed two centromeric and two episomal vectors harbouring KanMXR and ClonNATR as dominant drug resistance markers, respectively. We also constructed the plasmid pGRCRE that allows the Cre recombinase-mediated marker recycling during multiple gene deletions. As proof of concept, pGRCRE was successfully used to rescue the kanMX-loxP module in Z. Rouxii ATCC 42981 G418-resistant mutants previously constructed by replacing the MATαP expression locus with the loxP-kanMX-loxP cassette.

  • Zygosaccharomyces Rouxii Trk1 is an efficient potassium transporter providing yeast cells with high lithium tolerance.
    FEMS yeast research, 2015
    Co-Authors: Olga Zimmermannova, Hana Sychrová, Ana Salazar, Jose Ramos
    Abstract:

    Zygosaccharomyces Rouxii is an osmotolerant yeast growing in the presence of high concentrations of salts and/or sugars. The maintenance of intracellular potassium homeostasis is essential for osmostress adaptation. Zygosaccharomyces Rouxii is endowed with only one typical potassium transporter (ZrTrk1). We characterized ZrTrk1 activity and its contribution to various physiological parameters in detail. Our results show that ZrTrk1 is a high-affinity K(+) transporting system efficiently discriminating between K(+) and Li(+) and indicate the presence of another, currently unknown K(+) importing system with a low affinity in Z. Rouxii cells. Upon ZrTrk1 heterologous expression in Saccharomyces cerevisiae, it confers cells with a remarkably high lithium tolerance (even to wild-type strains) due to preventing Li(+) influx into cells, and is able to complement a plasma-membrane hyperpolarization and cell sensitivity to cationic compounds caused by the lack of endogenous K(+) transporters. Intracellular pH measurements with pHluorin, whose coding sequence was integrated into the genome, showed that the expression of ZrTrk1 also complements a decrease in intracellular pH in S. cerevisiae trk1Δ trk2Δ cells. Our data corroborate a tight connection between potassium and proton transporters in yeasts and provide new insights into Z. Rouxii cation homeostasis and the basis of its high osmotolerance.

  • a hydrophobic filter confers the cation selectivity of Zygosaccharomyces Rouxii plasma membrane na h antiporter
    Journal of Molecular Biology, 2015
    Co-Authors: Olga Kinclovazimmermannova, Pierre Falson, Denis Cmunt, Hana Sychrová
    Abstract:

    Abstract Na+/H+ antiporters may recognize all alkali-metal cations as substrates but may transport them selectively. Plasma-membrane Zygosaccharomyces Rouxii Sod2-22 antiporter exports Na+ and Li+, but not K+. The molecular basis of this selectivity is unknown. We combined protein structure modeling, site-directed mutagenesis, phenotype analysis and cation efflux measurements to localize and characterize the cation selectivity region. A three-dimensional model of the ZrSod2-22 transmembrane domain was generated based on the X-ray structure of the Escherichia coli NhaA antiporter and primary sequence alignments with homologous yeast antiporters. The model suggested a close proximity of Thr141, Ala179 and Val375 from transmembrane segments 4, 5 and 11, respectively, forming a hydrophobic hole in the putative cation pathway's core. A series of mutagenesis experiments verified the model and showed that structural modifications of the hole resulted in altered cation selectivity and transport activity. The triple ZrSod2-22 mutant T141S-A179T-V375I gained K+ transport capacity. The point mutation A179T restricted the antiporter substrate specificity to Li+ and reduced its transport activity, while serine at this position preserved the native cation selectivity. The negative effect of the A179T mutation can be eliminated by introducing a second mutation, T141S or T141A, in the preceding transmembrane domain. Our experimental results confirm that the three residues found through modeling play a central role in the determination of cation selectivity and transport activity in Z. Rouxii Na+/H+ antiporter and that the cation selectivity can be modulated by repositioning a single local methyl group.

  • the high capacity specific fructose facilitator zrffz1 is essential for the fructophilic behavior of Zygosaccharomyces Rouxii cbs 732t
    Eukaryotic Cell, 2014
    Co-Authors: Maria Jose Leandro, Catarina Prista, Maria C Loureirodias, Sara Cabral, Hana Sychrová
    Abstract:

    Zygosaccharomyces Rouxii is a fructophilic yeast that consumes fructose preferably to glucose. This behavior seems to be related to sugar uptake. In this study, we constructed Z. Rouxii single-, double-, and triple-deletion mutants in the UL4 strain background (a ura3 strain derived from CBS 732T) by deleting the genes encoding the specific fructose facilitator Z. Rouxii Ffz1 (ZrFfz1), the fructose/glucose facilitator ZrFfz2, and/or the fructose symporter ZrFsy1. We analyzed the effects on the growth phenotype, on kinetic parameters of fructose and glucose uptake, and on sugar consumption profiles. No growth phenotype was observed on fructose or glucose upon deletion of FFZ genes. Deletion of ZrFFZ1 drastically reduced fructose transport capacity, increased glucose transport capacity, and eliminated the fructophilic character, while deletion of ZrFFZ2 had almost no effect. The strain in which both FFZ genes were deleted presented even higher consumption of glucose than strain Zrffz1Δ, probably due to a reduced repressing effect of fructose. This study confirms the molecular basis of the Z. Rouxii fructophilic character, demonstrating that ZrFfz1 is essential for Z. Rouxii fructophilic behavior. The gene is a good candidate to improve the fructose fermentation performance of industrial Saccharomyces cerevisiae strains.

  • ZrFsy1, a high-affinity fructose/H+ symporter from fructophilic yeast Zygosaccharomyces Rouxii.
    PloS one, 2013
    Co-Authors: Hana Sychrová, Maria C. Loureiro-dias
    Abstract:

    Zygosaccharomyces Rouxii is a fructophilic yeast than can grow at very high sugar concentrations. We have identified an ORF encoding a putative fructose/H+ symporter in the Z. Rouxii CBS 732 genome database. Heterologous expression of this ORF in a S. cerevisiae strain lacking its own hexose transporters (hxt-null) and subsequent kinetic characterization of its sugar transport activity showed it is a high-affinity low-capacity fructose/H+ symporter, with Km 0.45±0.07 mM and Vmax 0.57±0.02 mmol h−1 (gdw) −1. We named it ZrFsy1. This protein also weakly transports xylitol and sorbose, but not glucose or other hexoses. The expression of ZrFSY1 in Z. Rouxii is higher when the cells are cultivated at extremely low fructose concentrations (

M. Combina - One of the best experts on this subject based on the ideXlab platform.

  • Reduction of Zygosaccharomyces Rouxii Population in Concentrated Grape Juices by Thermal Pasteurization and Hydrostatic High Pressure Processing
    Food and Bioprocess Technology, 2019
    Co-Authors: M. C. Rojo, M. Cristiani, Natalia Szerman, M. L. Gonzalez, M. C. Lerena, L. A. Mercado, M. Combina
    Abstract:

    Zygosaccharomyces Rouxii is the most frequent spoilage yeast species detected in concentrated grape juice. In order to reduce Z. Rouxii populations and consequently extend the microbiological shelf life of this product, different programs of thermal pasteurization and high hydrostatic pressures processing were evaluated. Results showed that pasteurization temperatures higher than 75 °C are necessary to reduce Z. Rouxii population in concentrated grape juice. Reduction of 7 logarithms can be reached after 90 s at 75 and 80 °C, and 5 s at 85 °C of pasteurization treatment. High hydrostatic pressure treatment above 500 MPa for 2 min are necessary to reduce 7 logarithms of Z. Rouxii population and to significantly extend the shelf life of concentrate grape juice. Extension of holding times from 3 to 5 min, at the different high hydrostatic pressures evaluated, did not improve the Z. Rouxii population reduction, nor the shelf life extension of concentrate grape juice. In conclusion, thermal pasteurization and high hydrostatic pressure could be suitable treatments to achieve the reduction of Z. Rouxii population below the recommendation limit (102 CFU/g) and extension of the microbiological shelf life of concentrate grape juice.

  • Incidence of osmophilic yeasts and Zygosaccharomyces Rouxii during the production of concentrate grape juices.
    Food microbiology, 2016
    Co-Authors: Maria Cecilia Rojo, L. A. Mercado, C. Torres Palazzolo, R. Cuello, Maria Micaela Gonzalez, F. Guevara, M.l. Ponsone, Claudio Martínez, M. Combina
    Abstract:

    Zygosaccharomyces Rouxii is the main spoilage yeast of grape juice concentrates. Detection and identification of Z. Rouxii during the production of grape juice concentrate is critical to prevent spoilage in the final product. In this work, three grape juice concentrate processing plants were assessed by identifying osmophilic yeasts in juices and surfaces during different stages of a complete production line. Subsequently, molecular typing of Z. Rouxii isolates was done to determine the strain distribution of this spoilage yeast. Osmotolerant yeast species, other than Z. Rouxii, were mainly recovered from processing plant environments. Z. Rouxii was only isolated from surface samples with grape juice remains. Z. Rouxii was largely isolated from grape juice samples with some degree of concentration. Storage of grape juice pre-concentrate and concentrate allowed an increase in the Z. Rouxii population. A widely distributed dominant molecular Z. Rouxii pattern was found in samples from all three processing plants, suggesting resident microbes inside the plant.

  • evaluation of different chemical preservatives to control Zygosaccharomyces Rouxii growth in high sugar culture media
    Food Control, 2015
    Co-Authors: Maria Cecilia Rojo, M. C. Lerena, M. Combina, F Arroyo N Lopez, Laura Mercado, Adriana Mabel Torres
    Abstract:

    Abstract Zygosaccharomyces Rouxii is an osmophilic yeast responsible for a large amount of economic loss in high sugar food production. Statistical modelling techniques were used in the present study to assess the individual effects of different chemical preservatives (potassium sorbate, sodium benzoate, dimethyldicarbonate, vanillin, ferulic, p-coumaric and caffeic acids) to control the growth of a cocktail of five yeast strains belonging to this species and isolated from spoilt concentrated grape juices. None of the preservatives assayed were able to completely inhibit the Z. Rouxii growth. However, the mathematical models obtained in a high sugar culture media showed that especially four preservatives (potassium sorbate, sodium benzoate, dimethyldicarbonate and vanillin) were the best options to control the growth of this microorganism, obtaining a maximum reduction on yeast growth of approximately 40%. On the contrary, p-coumaric and caffeic acids were the preservatives with the lower effects, which only showed a maximum growth reduction percentage of approximately 15%. Results obtained in this paper could be very useful for industry for a better control of this spoilage yeast in concentrated grape juice.

  • effects of ph and sugar concentration in Zygosaccharomyces Rouxii growth and time for spoilage in concentrated grape juice at isothermal and non isothermal conditions
    Food Microbiology, 2014
    Co-Authors: Maria Cecilia Rojo, M. C. Lerena, M. Combina, F Arroyo N Lopez, Laura Mercado, A Torres
    Abstract:

    The effect of pH (1.7–3.2) and sugar concentration (64–68 °Brix) on the growth of Zygosaccharomyces Rouxii MC9 using response surface methodology was studied. Experiments were carried out in concentrated grape juice inoculated with Z. Rouxii at isothermal conditions (23 °C) for 60 days. pH was the variable with the highest effect on growth parameters (potential maximum growth rate and lag phase duration), although the effect of sugar concentration were also significant. In a second experiment, the time for spoilage by this microorganism in concentrated grape juice was evaluated at isothermal (23 °C) and non-isothermal conditions, in an effort to reproduce standard storage and overseas shipping temperature conditions, respectively. Results show that pH was again the environmental factor with the highest impact on delaying the spoilage of the product. Thereby, a pH value below 2.0 was enough to increase the shelf life of the product for more than 60 days in both isothermal and non-isothermal conditions. The information obtained in the present work could be used by producers and buyers to predict the growth and time for spoilage of Z. Rouxii in concentrated grape juice.

Youichi Tamai - One of the best experts on this subject based on the ideXlab platform.

  • co expression of the na h antiporter and h atpase genes of the salt tolerant yeast Zygosaccharomyces Rouxii in saccharomyces cerevisiae
    Fems Yeast Research, 2005
    Co-Authors: Yasuo Watanabe, Naoko Oshima, Youichi Tamai
    Abstract:

    We cloned two genes from the salt-tolerant yeast Zygosaccharomyces Rouxii: ZrSOD2 for the cell membrane Na+/H+-antiporter and ZrPMA1 for the cell membrane H+-ATPase. The products of these genes play cooperative roles in the salt-tolerance of Z. Rouxii, and the function of the ZrPMA1 product is regulated at the transcription level. We constructed a yeast expression vector that is able to co-express the ZrSOD2 and ZrPMA1 genes. Single expression of ZrSOD2 was effective in conferring salt-tolerance, and although a slight synergic effect was observed with co-expression of ZrSOD2 and ZrPMA1, the usefulness of this co-expression is likely to be minimal with regard to salt-tolerance.

  • heterologous expression of Zygosaccharomyces Rouxii glycerol 3 phosphate dehydrogenase gene zrgpd1 and glycerol dehydrogenase gene zrgcy1 in saccharomyces cerevisiae
    Fems Yeast Research, 2004
    Co-Authors: Yasuo Watanabe, Syoko Tsuchimoto, Youichi Tamai
    Abstract:

    We examined the effects of heterologous expression of the open reading frames (ORF) of two genes on salt tolerance and glycerol production in a Saccharomyces cerevisiae strain deficient in glycerol synthesis (gpd1Δgpd2Δ). When the ORF of the Zygosaccharomyces Rouxii glycerol 3-phosphate dehydrogenase gene (ZrGPD1) was expressed under the control of the GAL10 promoter, salt tolerance and glycerol production increased; when the ORF of the glycerol dehydrogenase gene (ZrGCY1) was expressed under the control of the GAL1 promoter, no such changes were observed. Zrgcy1p had a weak effect on glycerol production. These results suggest that Zrgpd1p is the primary enzyme involved in Z. Rouxii glycerol production, following a mechanism similar to that of S. cerevisiae (Gpd1p). When the ORFs of the S. cerevisiae glycerol 3-phosphatase gene (GPP2) and ZrGPD1 were simultaneously expressed, glycerol production increased, compared with that in yeast expressing only ZrGPD1.

  • cloning of glycerol 3 phosphate dehydrogenase genes zrgpd1 and zrgpd2 and glycerol dehydrogenase genes zrgcy1 and zrgcy2 from the salt tolerant yeast Zygosaccharomyces Rouxii
    Yeast, 2001
    Co-Authors: Tomoko Iwaki, Youichi Tamai, Sachko Kurono, Yuki Yokose, Kenji Kubota, Yasuo Watanabe
    Abstract:

    The ZrGPD1 and ZrGPD2 genes encoding putative glycerol-3-phosphate dehydrogenases were isolated from the salt-tolerant yeast, Zygosaccharomyces Rouxii. Both genes are homologous to GPD1 of Saccharomyces cerevisiae and are constitutively expressed in Z. Rouxii cells. Putative glycerol dehydrogenase genes, ZrGCY1 and ZrGCY2, which are highly homologous to GCY1 of S. cerevisiae, were also isolated. Since the level of transcripts of ZrGCY1 and ZrGCY2 increased in Z. Rouxii cells subjected to salt stress, it is suggested that the pathway of the signal transduction of salt stress controls the expression of these genes. The Accession Nos of these sequences in GenBank are as follows: ZrGPD1, AB047394; ZrGPD2, AB047395; ZrGCY1, AB047396; ZrGCY2, AB047397. Copyright © 2001 John Wiley & Sons, Ltd.

  • characterization of the na atpase gene zena1 from the salt tolerant yeast Zygosaccharomyces Rouxii
    Journal of Bioscience and Bioengineering, 1999
    Co-Authors: Yasuo Watanabe, Tomoko Iwaki, Yasutaka Shimono, Akihiro Ichimiya, Yoshiaki Nagaoka, Youichi Tamai
    Abstract:

    Abstract In order to clarify the relationship between the salt tolerance of Zygosaccharomyces Rouxii and the function of Na+-ATPase, a gene which exhibited homology to the Na+-ATPase gene (ZENA1) of Saccharomyces cerevisiae was isolated from Z. Rouxii. This newly isolated gene (ZENA1) encoded a product of 1048 amino acids. The predicted amino-acid sequence of Zena1p was highly homologous to that of S. cerevisiae Ena1p and Ena2p, and Schwanniomyces occidentalis Ena1p and Ena2p, but showed low homology to that of Zpma1p, which is the product of the Z. Rouxii plasma membrane H+.ATPase gene (ZENA1). Zena1p shares the peptide motifs which have been suggested to participate in the function of ATPase. Expression of ZENA1 was observed, but was independent of NaCl shock. When ZENA1 was expressed in salt-sensitive S. cerevisiae under the regulation of a GAL1 promoter by using the expression vector pYES2, salt tolerance of the transformants was observed. The growth characteristics of Zena1Δ-disruptants of Z. Rouxii and the pH profiles of their plasma membrane ATPase activity were almost the same as those of the wild-type strain, indicating that the function of Zena1p is of little relevance to the salt tolerance property of Z. Rouxii. By considering the close relationship between the salt tolerance of Z. Rouxii and the function of its Na+/H+-antiporter, we concluded that the extrusion of Na+ across the plasma membrane in Z. Rouxii cells might be carried out mainly via the function of the Na+/H+-antiporter in a high salinity environment.

  • characterization of na h antiporter gene closely related to the salt tolerance of yeast Zygosaccharomyces Rouxii
    Yeast, 1995
    Co-Authors: Yasuo Watanabe, Satoko Miwa, Youichi Tamai
    Abstract:

    In order to clarify the relationship between salt-tolerance of Zygosaccharomyces Rouxii and the function of Na+/H(+)-antiporter, a gene was isolated from Z. Rouxii which exhibited homology to the Na+/H(+)-antiporter gene (sod2) from Schizosaccharomyces pombe. This newly isolated gene (Z-SOD2) encoded a product of 791 amino acids, which was larger than the product encoded by its Sz. pombe homologue. The predicted amino-acid sequence of Z-Sod2p was highly homologous to that of the Sz. pombe protein, but included an extra-hydrophilic stretch in the C-terminal region. The expression of Z-SOD2 was constitutive and independent of NaCl-shock. Z-SOD2-disruptants of Z. Rouxii did not grow in media supplemented with 3 M-NaCl, but grew well in the presence of 50% sorbitol, indicating that the function of Z-SOD2 was closely related to the salt-tolerance of Z. Rouxii. Several genes are also compared and discussed in relation to the salt-tolerance of Z. Rouxii.

Yasuo Watanabe - One of the best experts on this subject based on the ideXlab platform.

  • co expression of the na h antiporter and h atpase genes of the salt tolerant yeast Zygosaccharomyces Rouxii in saccharomyces cerevisiae
    Fems Yeast Research, 2005
    Co-Authors: Yasuo Watanabe, Naoko Oshima, Youichi Tamai
    Abstract:

    We cloned two genes from the salt-tolerant yeast Zygosaccharomyces Rouxii: ZrSOD2 for the cell membrane Na+/H+-antiporter and ZrPMA1 for the cell membrane H+-ATPase. The products of these genes play cooperative roles in the salt-tolerance of Z. Rouxii, and the function of the ZrPMA1 product is regulated at the transcription level. We constructed a yeast expression vector that is able to co-express the ZrSOD2 and ZrPMA1 genes. Single expression of ZrSOD2 was effective in conferring salt-tolerance, and although a slight synergic effect was observed with co-expression of ZrSOD2 and ZrPMA1, the usefulness of this co-expression is likely to be minimal with regard to salt-tolerance.

  • heterologous expression of Zygosaccharomyces Rouxii glycerol 3 phosphate dehydrogenase gene zrgpd1 and glycerol dehydrogenase gene zrgcy1 in saccharomyces cerevisiae
    Fems Yeast Research, 2004
    Co-Authors: Yasuo Watanabe, Syoko Tsuchimoto, Youichi Tamai
    Abstract:

    We examined the effects of heterologous expression of the open reading frames (ORF) of two genes on salt tolerance and glycerol production in a Saccharomyces cerevisiae strain deficient in glycerol synthesis (gpd1Δgpd2Δ). When the ORF of the Zygosaccharomyces Rouxii glycerol 3-phosphate dehydrogenase gene (ZrGPD1) was expressed under the control of the GAL10 promoter, salt tolerance and glycerol production increased; when the ORF of the glycerol dehydrogenase gene (ZrGCY1) was expressed under the control of the GAL1 promoter, no such changes were observed. Zrgcy1p had a weak effect on glycerol production. These results suggest that Zrgpd1p is the primary enzyme involved in Z. Rouxii glycerol production, following a mechanism similar to that of S. cerevisiae (Gpd1p). When the ORFs of the S. cerevisiae glycerol 3-phosphatase gene (GPP2) and ZrGPD1 were simultaneously expressed, glycerol production increased, compared with that in yeast expressing only ZrGPD1.

  • cloning of glycerol 3 phosphate dehydrogenase genes zrgpd1 and zrgpd2 and glycerol dehydrogenase genes zrgcy1 and zrgcy2 from the salt tolerant yeast Zygosaccharomyces Rouxii
    Yeast, 2001
    Co-Authors: Tomoko Iwaki, Youichi Tamai, Sachko Kurono, Yuki Yokose, Kenji Kubota, Yasuo Watanabe
    Abstract:

    The ZrGPD1 and ZrGPD2 genes encoding putative glycerol-3-phosphate dehydrogenases were isolated from the salt-tolerant yeast, Zygosaccharomyces Rouxii. Both genes are homologous to GPD1 of Saccharomyces cerevisiae and are constitutively expressed in Z. Rouxii cells. Putative glycerol dehydrogenase genes, ZrGCY1 and ZrGCY2, which are highly homologous to GCY1 of S. cerevisiae, were also isolated. Since the level of transcripts of ZrGCY1 and ZrGCY2 increased in Z. Rouxii cells subjected to salt stress, it is suggested that the pathway of the signal transduction of salt stress controls the expression of these genes. The Accession Nos of these sequences in GenBank are as follows: ZrGPD1, AB047394; ZrGPD2, AB047395; ZrGCY1, AB047396; ZrGCY2, AB047397. Copyright © 2001 John Wiley & Sons, Ltd.

  • characterization of the na atpase gene zena1 from the salt tolerant yeast Zygosaccharomyces Rouxii
    Journal of Bioscience and Bioengineering, 1999
    Co-Authors: Yasuo Watanabe, Tomoko Iwaki, Yasutaka Shimono, Akihiro Ichimiya, Yoshiaki Nagaoka, Youichi Tamai
    Abstract:

    Abstract In order to clarify the relationship between the salt tolerance of Zygosaccharomyces Rouxii and the function of Na+-ATPase, a gene which exhibited homology to the Na+-ATPase gene (ZENA1) of Saccharomyces cerevisiae was isolated from Z. Rouxii. This newly isolated gene (ZENA1) encoded a product of 1048 amino acids. The predicted amino-acid sequence of Zena1p was highly homologous to that of S. cerevisiae Ena1p and Ena2p, and Schwanniomyces occidentalis Ena1p and Ena2p, but showed low homology to that of Zpma1p, which is the product of the Z. Rouxii plasma membrane H+.ATPase gene (ZENA1). Zena1p shares the peptide motifs which have been suggested to participate in the function of ATPase. Expression of ZENA1 was observed, but was independent of NaCl shock. When ZENA1 was expressed in salt-sensitive S. cerevisiae under the regulation of a GAL1 promoter by using the expression vector pYES2, salt tolerance of the transformants was observed. The growth characteristics of Zena1Δ-disruptants of Z. Rouxii and the pH profiles of their plasma membrane ATPase activity were almost the same as those of the wild-type strain, indicating that the function of Zena1p is of little relevance to the salt tolerance property of Z. Rouxii. By considering the close relationship between the salt tolerance of Z. Rouxii and the function of its Na+/H+-antiporter, we concluded that the extrusion of Na+ across the plasma membrane in Z. Rouxii cells might be carried out mainly via the function of the Na+/H+-antiporter in a high salinity environment.

  • characterization of na h antiporter gene closely related to the salt tolerance of yeast Zygosaccharomyces Rouxii
    Yeast, 1995
    Co-Authors: Yasuo Watanabe, Satoko Miwa, Youichi Tamai
    Abstract:

    In order to clarify the relationship between salt-tolerance of Zygosaccharomyces Rouxii and the function of Na+/H(+)-antiporter, a gene was isolated from Z. Rouxii which exhibited homology to the Na+/H(+)-antiporter gene (sod2) from Schizosaccharomyces pombe. This newly isolated gene (Z-SOD2) encoded a product of 791 amino acids, which was larger than the product encoded by its Sz. pombe homologue. The predicted amino-acid sequence of Z-Sod2p was highly homologous to that of the Sz. pombe protein, but included an extra-hydrophilic stretch in the C-terminal region. The expression of Z-SOD2 was constitutive and independent of NaCl-shock. Z-SOD2-disruptants of Z. Rouxii did not grow in media supplemented with 3 M-NaCl, but grew well in the presence of 50% sorbitol, indicating that the function of Z-SOD2 was closely related to the salt-tolerance of Z. Rouxii. Several genes are also compared and discussed in relation to the salt-tolerance of Z. Rouxii.

M. C. Lerena - One of the best experts on this subject based on the ideXlab platform.

  • Reduction of Zygosaccharomyces Rouxii Population in Concentrated Grape Juices by Thermal Pasteurization and Hydrostatic High Pressure Processing
    Food and Bioprocess Technology, 2019
    Co-Authors: M. C. Rojo, M. Cristiani, Natalia Szerman, M. L. Gonzalez, M. C. Lerena, L. A. Mercado, M. Combina
    Abstract:

    Zygosaccharomyces Rouxii is the most frequent spoilage yeast species detected in concentrated grape juice. In order to reduce Z. Rouxii populations and consequently extend the microbiological shelf life of this product, different programs of thermal pasteurization and high hydrostatic pressures processing were evaluated. Results showed that pasteurization temperatures higher than 75 °C are necessary to reduce Z. Rouxii population in concentrated grape juice. Reduction of 7 logarithms can be reached after 90 s at 75 and 80 °C, and 5 s at 85 °C of pasteurization treatment. High hydrostatic pressure treatment above 500 MPa for 2 min are necessary to reduce 7 logarithms of Z. Rouxii population and to significantly extend the shelf life of concentrate grape juice. Extension of holding times from 3 to 5 min, at the different high hydrostatic pressures evaluated, did not improve the Z. Rouxii population reduction, nor the shelf life extension of concentrate grape juice. In conclusion, thermal pasteurization and high hydrostatic pressure could be suitable treatments to achieve the reduction of Z. Rouxii population below the recommendation limit (102 CFU/g) and extension of the microbiological shelf life of concentrate grape juice.

  • evaluation of different chemical preservatives to control Zygosaccharomyces Rouxii growth in high sugar culture media
    Food Control, 2015
    Co-Authors: Maria Cecilia Rojo, M. C. Lerena, M. Combina, F Arroyo N Lopez, Laura Mercado, Adriana Mabel Torres
    Abstract:

    Abstract Zygosaccharomyces Rouxii is an osmophilic yeast responsible for a large amount of economic loss in high sugar food production. Statistical modelling techniques were used in the present study to assess the individual effects of different chemical preservatives (potassium sorbate, sodium benzoate, dimethyldicarbonate, vanillin, ferulic, p-coumaric and caffeic acids) to control the growth of a cocktail of five yeast strains belonging to this species and isolated from spoilt concentrated grape juices. None of the preservatives assayed were able to completely inhibit the Z. Rouxii growth. However, the mathematical models obtained in a high sugar culture media showed that especially four preservatives (potassium sorbate, sodium benzoate, dimethyldicarbonate and vanillin) were the best options to control the growth of this microorganism, obtaining a maximum reduction on yeast growth of approximately 40%. On the contrary, p-coumaric and caffeic acids were the preservatives with the lower effects, which only showed a maximum growth reduction percentage of approximately 15%. Results obtained in this paper could be very useful for industry for a better control of this spoilage yeast in concentrated grape juice.

  • effects of ph and sugar concentration in Zygosaccharomyces Rouxii growth and time for spoilage in concentrated grape juice at isothermal and non isothermal conditions
    Food Microbiology, 2014
    Co-Authors: Maria Cecilia Rojo, M. C. Lerena, M. Combina, F Arroyo N Lopez, Laura Mercado, A Torres
    Abstract:

    The effect of pH (1.7–3.2) and sugar concentration (64–68 °Brix) on the growth of Zygosaccharomyces Rouxii MC9 using response surface methodology was studied. Experiments were carried out in concentrated grape juice inoculated with Z. Rouxii at isothermal conditions (23 °C) for 60 days. pH was the variable with the highest effect on growth parameters (potential maximum growth rate and lag phase duration), although the effect of sugar concentration were also significant. In a second experiment, the time for spoilage by this microorganism in concentrated grape juice was evaluated at isothermal (23 °C) and non-isothermal conditions, in an effort to reproduce standard storage and overseas shipping temperature conditions, respectively. Results show that pH was again the environmental factor with the highest impact on delaying the spoilage of the product. Thereby, a pH value below 2.0 was enough to increase the shelf life of the product for more than 60 days in both isothermal and non-isothermal conditions. The information obtained in the present work could be used by producers and buyers to predict the growth and time for spoilage of Z. Rouxii in concentrated grape juice.

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